Can I take Desmopressin and Ketoconazole together?
Drug interaction guide
Originally published 14 Mar 2026
Meets Patient’s editorial guidelines
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Taking these two medicines together can significantly increase the amount of desmopressin in your blood. This can lead to your body holding onto too much water, which can cause a dangerous drop in your blood salt levels (hyponatraemia). Symptoms to watch for include severe headache, nausea, vomiting, confusion, or feeling very drowsy.
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Why this happens
Ketoconazole blocks a specific enzyme in your liver and gut (called CYP3A4) that is responsible for breaking down many medicines. When this enzyme is blocked, desmopressin stays in your system much longer and reaches higher levels than intended.
What you should do
Back to contentsYou should speak to your doctor before taking these medicines together. They may want to monitor your blood salt levels or adjust your dose. If you experience a sudden headache, confusion, or feel unusually sick while taking both, seek medical advice immediately.
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Using other medicines
Back to contentsTaking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.
Disclaimer
This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.
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Article history
The information on this page is written and peer reviewed by qualified clinicians.
14 Mar 2026 | Originally published

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